I always write an elaborate piece for my blog. It's better that way. I believe it should be around a thousand words long. But I prefer to do around 1500-2k words for my blogs. This shows your expertise upon the area you're writing. The more you convey the more visitors are likely to return. For example, if you're writing blog on mobile apps, it's always better to convey to people what types they are, what are their functions, and how did you find it yourself when you used it. Now, this using yourself part is very important as the success of your blog depends on what experiences you've really had with the services that you're writing about. People tend to relate more to those ideas that have been tested by other people.
I partially agree with this. I think it's important to show how knowledgeable you are about the subject, especially if insight is what your potential viewer will be looking for in your niche, but lengthy posts will drive people away if that's not fitting. Take how-tos, for instance. You can explain every little detail about each step they will have to follow, but people ultimately just want to get the thing done. On the contrary, researches, descriptive articles and reviews greatly benefit from 1000+ words posts, and short ones will probably be looked down upon and labelled as superficial.
So, the shocking answer is once again: it depends. The number of words is proportional to the degree of insight the subject you're broaching requires. If I have to make a few esteems, I'd say 500~ words for how-tos and tutorials, and even some kind of news, even better if you let images do the talk for you, 1000+ for the aforementioned examples, and somewhere in-between for anything that doesn't fall in neither category.
